The invention relates to a door drive for a motor vehicle door. Furthermore, the invention relates to such a motor vehicle door.
The side doors of the vast majority of motor vehicles which are to be found nowadays in road traffic are still opened and closed manually. In order to assist and limit a respective opening movement, in this context usually arrestor straps are used which are of differing designs and have respective sliding block guides which are mounted with one of their ends on a corresponding door pillar to which the side door is fastened and which interact with a usually spring-supported ball element or roller element which is attached to the door shell side and which rolls on the sliding block guide of the arrestor strap. As a result corresponding intermediate positions and final positions during the opening of the motor vehicle door can be latched.
In order to be able to avoid the collision of the motor vehicle door with an obstacle, for example an adjacently parked motor vehicle, there are already various approaches for limiting the opening swinging movement of the respective motor vehicle door. In this context, use is also made, for example, of combinations of arrestor straps with corresponding actuators which are, for example, sensor-controlled.
In addition to these possibilities for limiting the opening swinging movement, door drives by means of which not only the swinging range of the respective motor vehicle door can be limited but also at least the opening movement thereof, and if appropriate also the closing movement thereof, takes place in a driven fashion, have now become established, in particular in executive motor vehicles. An example of such a door drive is known from WO 2015/048876 A1, in which a lever element of an arrestor strap type is mounted, on the one hand, on a door pillar to which the motor vehicle door is fastened, and which is connected, on the other hand, to an adjustable drive element of a drive device which is arranged on the motor vehicle door. This drive element is formed by a gearwheel which meshes with the lever element or arrestor strap. Owing to the installation space conditions within the motor vehicle door, the drive device must, however, be arranged either directly on a frame element which adjoins the door pillar to which the motor vehicle door is fastened, or else said drive device must be provided at a short distance from this frame element. As a result, during opening and closing very high torques and forces are produced which act on the drive device. This gives rise to high mechanical loading and generation of noise, as well as to imprecise movement of the motor vehicle door.
A similar problem also arises in other known door drives which are all arranged within the door shell near to the frame element thereof which adjoins the door pillar to which the motor vehicle door is fastened.
The object of the present invention is therefore to provide a door drive and a side door of the type mentioned at the beginning, by means of which door drive and side door a much more precise and quieter adjustment of the motor vehicle door can be implemented.
This and other objects are achieved by a door drive and a motor vehicle door in accordance with embodiments of the invention.
The door drive mentioned at the beginning is distinguished according to the invention by the fact that the drive element of the drive device, which drive element extends at least indirectly with the lever element between the motor vehicle shell, in particular a respective door pillar, and the motor vehicle door, is embodied as a rocker element which can be moved about a bearing axis which comprises a first lever arm via which the rocker element is at least indirectly connected to an actuator of the drive device, and a second lever arm by means of which the rocker element is at least indirectly connected to the lever element. By providing this rocker element according to the invention it is possible according to the invention to make much better use of the installation space which is available within the motor vehicle door, with the result that in contrast to the previous prior art, not only can the drive device be arranged directly next to the frame element of the door shell which adjoins the door pillar to which the motor door is fastened, but also regions, for example on the outside or inside of a window device of the motor vehicle door can instead also be used for the arrangement of respective components of the drive device and, in particular, for use as swinging regions of the respective lever arms of the rocker element. By means of the better use of the free installation space within the motor vehicle door which is achieved in this way, it is possible to use correspondingly longer lever arms of the rocker element and of the other components of the drive device to carry out the adjustment of the motor vehicle door. The relatively long lever arms therefore permit smaller adjustment forces within the drive device, with the result that overall, in addition to other advantages, in particular a more precise adjustment or limitation of the opening movement as well as overall quieter adjustment of the motor vehicle door can be implemented.
The rocker element can be dimensioned and arranged advantageously here in such a way that favorable forces and torques as well as precise movement speeds of the motor vehicle door and an associated position detection process of obstacles in the opening region of the door can be implemented.
In addition to the actual drive, which comprises at least the outward movement and preferably also the closing movement, the drive device can also easily implement respective limitation of the opening movement of the motor vehicle door.
A further advantage of the door drive according to the invention is that it can easily be structurally integrated into an already existing motor vehicle door with a conventional arrestor strap. This means that the door drive can, for example, easily be used as a special equipment item in series-produced vehicles.
In a further refinement of the invention, the drive device serves both to open and to close the motor vehicle door. This permits, in a particularly comfortable fashion, the automatic control and movement of the motor vehicle door, for example by means of a gesture control or the like. In this context it is, in particular, also advantageous if the opening movement of the motor vehicle door is limited by means of the drive device before an obstacle is reached or impacted against, and therefore consequently the door drive also serves as a stop.
A further advantageous refinement of the invention provides that the bearing axle of the rocker element extends in the transverse direction of the motor vehicle door. The two bearing arms of the rocker element can therefore be dimensioned in a particularly favorable and correspondingly long fashion, with the result that forces and torques which are to be transmitted can preferably be kept relatively small and adjustment of the door can take place in a very accurate fashion.
In a further refinement of the invention, the first and the second lever arm of the rocker element are arranged offset with respect to one another, by a distance in the transverse direction of the motor vehicle door, at least with their respective bearing point, on the one hand, toward the lever element and, on the other hand, toward the actuator. By means of this offset, the respective lever arms can be implemented within different swinging regions or respective free installation spaces within the motor vehicle door. Therefore, despite sufficiently long lever arms, the free installation spaces within the motor vehicle door are utilized favorably.
In a further refinement of the invention, said distance between the two lever arms in the transverse direction of the motor vehicle door is matched to a width of a side window device of the motor vehicle door. Therefore, one of the lever arms may advantageously be moved in front of the side door device and the other of the lever arms can advantageously be moved behind the side window device in correspondingly free installation spaces of the motor vehicle door, without a collision occurring with the side window device during this swinging movement. As a result, it is again possible to select particularly favorable and long lever arms of the rocker element even though there is a side window device, which usually comprises a side window and at least one associated guide and/or associated drive elements.
Said distance can be generated here, for example, in two different ways: on the one hand, the distance can be generated by an axle stub in the region of the bearing axis of the rocker element, by means of which axle stub the two lever arms are spaced apart from one another. On the other hand, said distance can be generated by a lever arm region, running laterally in the transverse direction of the door, of at least one of the two lever arms of the rocker element. Both technical configurations provide here again the advantage that free installation spaces within the motor vehicle door can be used particularly favorably.
The invention also includes a motor vehicle door with a door drive as claimed in one of the patent claims described above, wherein the advantages of such a motor vehicle door result directly from the previously described advantages of the door drive.
In a further refinement of the invention, the motor vehicle door is distinguished by the fact that the rocker element is attached to a frame element of the door shell, which is arranged opposite a door pillar to which the motor vehicle door is fastened. As a result, this rocker element, or the bearing axis thereof, can be positioned in an optimum way in a free installation space, wherein favorable lever ratios can additionally be implemented.
Finally, it has proven advantageous if a through-opening for the lever element in the frame element, lying opposite the door pillar, of the door shell is provided in a central region of the hinge arrangement thereof, in particular in the central region between two hinges. This through-guidance of the lever element has proven particularly advantageous in so far as in this way forces which act on the lever element from the drive device are particularly favorably transmitted to both hinges or centrally to the hinge arrangement, with the result that for example the motor vehicle door does not lift up during its movement as a result of a corresponding application of force by the drive device.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.